Surprising new research shows that one of the world’s most popular beverages can shrink your waistline, increase calorie burn, strengthen your bones—and even boost brainpower. What’s more, this invigorating, health-enhancing drink may also reduce risk for heart disease, according to new studies presented at the 5th International Scientific Symposium on Tea & Human Health in Washington, DC.
In a comprehensive review of earlier studies, Dutch scientists found that 24-hour energy expenditure and fat oxidation rose when people drank a green tea/caffeine beverage. The tea-drinkers burned an additional 100 calories daily and fat oxidation rose 16 percent—indicating that fat cells were being broken down and burned for energy more quickly. In a related review, the researcher found that quaffing green tea daily lead to an average weight loss of nearly three pounds when the volunteers followed their usual diet.
By combining a green tea/caffeine mix and a low-calorie diet, overweight women in a recent randomized, double-blind placebo-controlled trial (the gold standard of scientific research) dropped 13 pounds over four months. Women with a high caffeine intake had greater reductions in body weight, fat mass and waist circumference, compared to those who consumed a low-caffeine placebo drink, reported scientists from Maastricht University in the Netherlands in the journal Obesity.
Why Does Green Tea Boost Weight Loss?
Several studies show that the antioxidant-rich brew increases thermogenesis (a biological process involved in burning calories). For example, a 2007 paper published in American Journal of Physiology: Regulatory, Integrative and Comparative Physiology reports that green tea combats the drop in metabolism that typically occurs during weight loss, thus improving calorie burn.
However, there’s scientific debate about which compounds in green tea explain its fat-burning effects. Although researchers used to credit caffeine, a 2011 meta-analysis of earlier research demonstrated that the mix of catechins (disease-fighting antioxidants) and caffeine is why green tea revs up both metabolism (so you burn more calories) and fat oxidation. Drinks that only contain caffeine also stimulate metabolism, but have no effect on fat breakdown, the study reported.